458 



ILLUSTRATIONS OF THE NATURAL ORDERS. 



(Periwinkle), Nerium (Oleander), and a great number of tropical 

 shrubs and trees. In nearly all, the juice is drastic or poisonous ; 

 it often yields Caoutchouc ; which in Sumatra is obtained from Ur- 

 ceola elastica, and in Madagascar from Vahea. Strangely enough 

 some species yield a sweet and harmless milk, such as Tabernae- 

 montana utilis, one of the South American Cow-trees. Also the 

 fruit of several species is edible and even delicious ; that of others 

 is a deadly poison. One kernel of Tanghinia venenifera of Mad- 



1068 



agascar will kill twenty people. The inner bark of Dogbane makes 

 a strong cordage, whence its name of Indian Hemp. 



887. Ord. Asclcpiadaceo; {Milkweed Family). Herbs or shrubs, 

 with milky juice, and mostly opposite entire leaves ; mainly differ- 

 ing from the px-eceding order (as they do from all other Exogenous 

 plants) by the peculiar connection of the stamens with the stigma, 

 and the cohesion of the pollen into wax-like or granular masses, 

 which are attached in pairs to five glands of the stigma, and re- 

 moved from the anther-cells usually by the agency of insects (Fig. 

 541 _ 545). Fruit consisting of two follicles. Seeds usually with 

 a silky coma and a large embryo. — Ex. Asclepias (Milkweed, or 

 Silk weed). The juice of the A. tuberosa (Pleurisy-root, Butterfly- 

 Aveed) is not milky. In all, it is bitter and acrid, and contains 

 Caoutchouc. The roots, &c. are diaphoretic, emetic, or cathartic. 

 The inner bark yields abundance of very long and fine, extremely 



FIG. 1064. Apocynum androsaemifolium. 1065. Flower, of the natural size. 1066. Sta- 

 mens with the anthers conniveut around the pistils. 1067. The pistils with their large com- 

 mon stigma. lOGS. Seed with its coma, or tuft of silky hairs. 



